What resolution is the human eye? What aperture range does it have?

[shocksyde]

I've been wondering this for a while, but keep forgetting to ask.

At what point will digital camera sensors equal the human eye in terms of resolution?

Also, the iris acts just as aperture blades, so has anyone ever come out with f stop numbers for the human eye?

Here's a pretty good link but it doesn't mention aperture.

 

[troytime]

good questions. I've heard in several trainings that the human eye can capture ~26 stops of light at any time, whereas the best digital cameras can only capture 5.

I don't know how true it is, or what exactly it means, but it sounds neat.

 

[corkyg]

. . . and the eyebrow is there to protect the eye.

 

[Flipped Gazelle]

Originally posted by: corkyg
. . . and the eyebrow is there to protect the eye.

I thought the eyebrow's there to arch and look sinister.

 

[jpeyton]

Resolution isn't that great; you can zoom in 100% on a digital photo and see detail you didn't notice in real life.

Sensitivity is pretty darn good, especially our signal-to-noise ratio.

Dynamic range is off the charts. Our eyes don't blow out highlights.

 

[996GT2]

Dynamic range of human eye is estimated to be around 25 f-stops...basically more than any camera can capture in a single exposure.

In terms of optics, the eye really isn't that good. To compensate, the eyes are constantly shifting, so the image projected on to the photoreceptors in the retina is constantly shifting. Then, as the signal goes through LGN and to V1, your brain actively processes these slightly different versions of the same image to create one large composite.

Your eyes have about 5 million cones and 100 million rods. The area of highest acuity in the eye, the fovea, is almost exclusively made up of cones. However, because the eyes are constantly scanning the surroundings, estimates have put the resolution of the eyes at over 500 megapixels.

 

[Alyx]

One good thing about our eyes to note, they usually don't have trouble hunting for focus in low light. That would probably cause a headache!

 

[jpeyton]

Originally posted by: 996GT2
However, because the eyes are constantly scanning the surroundings, estimates have put the resolution of the eyes at over 500 megapixels.

Even if that figure was true, the optics and image processing pipeline don't output anywhere near that resolution.

 

[magomago]

If you want to talk about how sensitive the eye is, it is sensitive enough to pick up a single photon. However, sensitivity to that doesn't mean that is what we see. If that were the case, our vision would be very noisy in the dark. Instead, there is a threshold that must be hit before the action potentials are sent up to the brain.

 

[Munky]

Originally posted by: magomago
If you want to talk about how sensitive the eye is, it is sensitive enough to pick up a single photon. However, sensitivity to that doesn't mean that is what we see. If that were the case, our vision would be very noisy in the dark. Instead, there is a threshold that must be hit before the action potentials are sent up to the brain.

Interesting... so does that mean we can have better night vision if there was a way to chemically lower the action threshold?

 

[Triumph]

Originally posted by: 996GT2
Dynamic range of human eye is estimated to be around 25 f-stops...basically more than any camera can capture in a single exposure.

I believe that is a bit of a misrepresentation, though. The human eye doesn't see 25 f-stops at the same time. I've read that it is more closely represented by about 10 stops, film can represent 8 or 9, digital 7 or 8. This is why you can look at what's in front of you and see the details in the shade, while your photograph is either blown out in the highlights or dark in the shadows. I'm not necessarily disagreeing with you, but it's a hard thing to measure. How many line pairs per millimeter does the eye need to resolve before you can say you can see something? What color is the image? Red turns to black in low light, while green is pronounced, for example. I'm sure people much smarter than us have asked all of these questions. In any event, the human eye is pretty amazing.

 

[finbarqs]

i've read that Fuji's S5 Pro can capture 13 stops of dynamic range. The new D3X can capture similar amount without any "special technology" that fuji uses. So if our eye can capture 25 stops of dynamic range, it wouldn't be unbelievable. Oh yeah, our pupils are our "aperture" mechanism. It constant "dilates" to adjust for exposure. You can say that Humans have the BEST AF ever!! BOOYA!

good test to this is shine a flash light into someone's eye, and you can see the "aperture" stop down! let it go, and it will open up! just like a camera lens!